Many child-resistant closure systems, or reversible child resistant closure systems in the child resistant configuration, require a user to push-down-and-turn the closure with respect to a container to remove the closure from the container. For example, U.S. Pat. No. 5,499,078 describes a push-down-and-turn container system having a container with a plurality of locking lug receivers on the outer circumference of the neck/rim of the container and a closure having a circumferential sidewall with corresponding locking lugs along the inner surface of the sidewall. To install the closure to the container, the locking lug receivers 10 each include a tapered ramp 12 as shown in FIG. 1 herein that guides the locking lugs of the closure into a notch 14 of the locking lug receiver 10 upon rotation of the closure. As shown, the notch 14 is formed between the tapered ramp 12 and a vertical member 16 of the locking lug receiver 10. Engagement of the locking lugs with the corresponding locking lug receivers 10 prevents the closure from being turned in the counter-clockwise direction, and thus prevents the closure from being removed from the container 1.
In order to remove the closure from the container 1, the user must apply downward pressure to the closure to disengage corresponding locking lugs 9 (as best shown in FIG. 4) of the closure from the locking lug receivers 10 of the container 1, then turn the closure such that the locking lugs 9 are disposed in an open area 18 between adjacent locking lug receivers 10, and finally lift the closure from the container 1. Thus, these types of closure systems are commonly referred to as push-down-and-turn systems.
Similarly, as exemplified in U.S. Pat. No. 8,662,331, many child resistant closure systems include a deflectable locking structure disposed along a rim on the neck of the container for releasably engaging a locking lug of the closure. To remove this closure from the container, the user pushes down on the deflectable locking structure of to disengage the locking lug of the closure.
While these types of closure systems are generally effective in preventing a child from removing the closure from the container, it is not impossible for children to open the containers (hence the name “child resistant”). In particular, a child playing with the closure system may apply downward pressure to the closure resulting in disengagement of the locking lugs from the locking receivers. Once the locking lugs are disengaged, it is generally easy to intentionally or unintentionally remove the closure from the container. Also, the child may even figure out how to open the container, such as by watching their parents or even reading instructions on top of the closure, and then be able to do so on their own.
What is needed therefore is at least an option for the user to apply an enhanced locking system to the closure system.